The Triumph Tiger 100 (T100) was a British motorcycle first made by Triumph at their Coventry factory for 1939.

With the runaway sales success of the Triumph Speed Twin, Edward Turner's mind turned to further developing the potential of his new parallel twin motor. The lighter and more powerful Tiger 100 was developed as a sports enthusiasts machine, where as with previous models the '100' referred to its claimed maximum speed.

Technical changes over the Speed Twin included forged alloy pistons, a very early use of the technology. Secondly, the cylinders were forged in a single casting and held in place by eight studs, instead of the Speed Twin's six. Thirdly, the Tiger 100 used a single Amal carburetor, possible thanks to the 360-degree firing interval of the two cylinders. Finished in silver and costing 5 more, new features included a larger fuel tank and detachable silencers.

In March 1939, Triumph came up with an unorthodox 'launch' of the new Tiger 100. Using a Tiger 100 and a Speed Twin straight from dealers showrooms, endurance was tested with a run of over 1800 miles from John O'Groats to Lands End in Cornwall then to the Brooklands circuit for six hours of continuous high-speed laps, where riders Ivan Wicksteed and David Whitworth averaged 78.5 miles per hour (126.3 km/h) with a final lap of 88.5 miles per hour (142.4 km/h), winning Triumph the Maudes Trophy. The Tiger100's sporting pretensions were later further proven through Freddie Clarke's 1939 lap record at Brooklands of 118.02 miles per hour (189.93 km/h) on a bored-out 503cc Tiger 100.

Historical Account: "Bombing Run" - The Triumph works was destroyed by German bombers on the night of November 14th, 1940 - along with much of the city of Coventry - bringing production of the Tiger 100 to an end until after the war. When Triumph recovered and began production again at Meriden, the Tiger 100 re-appeared with the new telescopic fork. In 1951, it gained a new close finned alloy cylinder barrel and factory race kits for independent racers. In 1953, a fully race-kitted model, the Tiger 100C, was available although only 560 were made.

1954 saw the first swinging-arm rear suspension models and the Tiger 100 was developed year-on-year alongside the other models in the range. The 1959 model was the last of the pre-units (separate engine/gearbox) and in 1960 it was completely redesigned in the new 'unit' style as the T100A. A long line of T100SS, T100C, T100R and others appeared during the sixties in the UK & export (mainly US) markets culminating in the Daytona variants which soldiered on until 1973. The historic Tiger name was revived by the new Hinckley Triumph company in 2001.